"The Council shall assess whether the conditions for transition beyond the first phase have been met, taking into account any applicable UN Security Council Resolution and consent by the Coastal States concerned." See the full
“The Council shall assess whether the conditions for transition beyond the first phase have been met, taking into account any applicable UN Security Council Resolution and consent by the Coastal States concerned.”
See the full text: European Union Naval Force – Mediterranean (Press statement, pdf): Contributing States: Currently 14 Member States (BE, DE, EL, ES, FI, FR, HU, IT, LT, LU, NL, SE, SI, UK).
Consent is needed for the EU to act within the territorial waters of another state (eg: Libya)